1. Field of the Invention
An energy conservation system to selectively control the temperature of water within a water storage tank based upon predicted hot water usage derived from historical data.
2. Description of the Prior Art
The amount of energy used to heat and cool most homes in the United States typically consumes a substantial portion of an annual energy budget. Hot water heating is another significant draw on the consumption of energy. Although many water heating options are available in the United States, storage water heaters are the most commonly used as such heaters are relatively easy and inexpensive to install. Energy cost for hot water production can be reduced by insulating hot water pipes leading from a water heater tank to plumbing fixtures and appliances in the home, providing an insulating jacket around a water heater's tank, lowering the water temperature maintained in a storage hot water heater's tank, and selectively reducing the amount of hot water used in the home for laundry, baths, showers, dishwashing, and other routine tasks. However, since the steps of lowering the pre-set temperature on a water heater thermostat and providing insulation each only contributes a maximum annual energy savings of approximately 5%, other means of energy savings are still needed. Another option for heating hot water is a tankless water heater. However, such systems have several disadvantages including limited flow rates and the potential need for special wiring. Moreover, people's usage patterns or habits routinely vary.
Also, these systems achieve the best energy savings when employed in homes having floor plans purposefully locating hot water faucets and appliances using hot water in consolidated locations so as to minimize the amount of plumbing conduit required, and where high efficiency fixtures are also used. Thus, with current limitations, water heating systems are not capable of providing the widespread residential energy reduction currently desired and needed for heating hot water in residential applications in the United States. Additional options for hot water generation in residential applications include heat pumps, as well as solar, integrated, and indirect systems. Even though some of these alternative systems have a lower operating cost than water heating systems, most have a higher installation cost. Other disadvantages of such alternative systems include limited suppliers and equipment availability, the need in indirect and integrated systems for heat exchanger installation, the need in solar systems for ample non-shaded roof space or other open area that receives a calculated minimum number of hours of solar radiation each day, and the difficulty in finding experienced installers.
In contrast, the present invention modifies the operation of the water heater by providing an automated system that learns to adjust current hot water availability from established patterns of hot water use. Energy savings through use of the present invention can be approximately 20% to 50% over that provided by a conventional water heater operated by a timer allowing the present invention system to typically recoup cost and installation expense in less than one year. No other known devices used for control of water heater activity so as to maintain a readily available supply of hot water for use upon demand, function in the same manner as the present invention or provide all of its features and advantages.